US4732870A
Expired / Lapsed
US
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Method of making complementary field effect transistors
Assignee: Fujitsu Ltd
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Filing: 1987-08-11
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Granted: 1988-03-22
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Expires: 2007-08-11
Abstract
Abstract A semiconductor device, e.g., a complementary circuit comprising an n-channel transistor (Qn) utilizing a two-dimensional electron gas and a p-channel transistor (Qp) utilizing a two-dimensional hole gas, comprises: a semi-insulating GaAs substrate; a channel layer of an i-type GaAs having n+-type source and drain regions and p+-type source and drain regions; a buffer layer of an i-type AlGaAs preventing carriers from passing therethrough; first and second control layers of GaAs or AlGaAs having n-type or p-type conductivity, these layers being epitaxially formed in sequence on the substrate by an MBE method or an MOCVD method; and metal electrodes formed on the first and second control layers, n+-type regions and p+-type regions.
Inventors
- 👤 Takashi Mimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:06
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/40; H10D30/47; H10D30/471; H10D30/475; H10D64/00; H10D64/60; H10D64/602; H10D84/00; H10D84/01; H10D84/02; H10D84/05
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
148 words
A method of producing a semiconductor device comprising the steps of: epitaxially forming a channel layer of an undoped single crystalline semiconductor on a semi-insulating single crystalline substrate; epitaxially forming a buffer layer of an undoped single crystalline semiconductor on said channel layer; epitaxially and selectively forming a first control layer of a doped single crystalline semiconductor on said buffer layer; epitaxially and selectively forming a second control layer of a doped single crystalline semiconductor on said buffer layer; forming a first control electrode and a second control electrode on said first control layer and said second control layer and said second control layer, respectively; forming a pair of impurity regions of a first conductivity type in said channel layer; forming a pair of impurity regions of a second conductivity type, opposite said first conductivity type, in said channel layer; and forming electrodes on said impurity regions, respectively.
Claim 2
Independent Claim
148 words
A method of producing a semiconductor device comprising the steps of: epitaxially forming a channel layer of an undoped single crystalline semiconductor on a semi-insulating single crystalline substrate; epitaxially forming a buffer layer of an undoped single crystalline semiconductor on said channel layer; epitaxially and selectively forming a first control layer of a doped single crystalline semiconductor on said buffer layer; epitaxially and selectively forming a second control layer of a doped single crystalline semiconductor on said buffer layer; forming a first control electrode and a second control electrode on said first control layer and said second control layer and said second control layer, respectively; forming a pair of impurity regions of a first conductivity type in said channel layer; forming a pair of impurity regions of a second conductivity type, opposite said first conductivity type, in said channel layer; and forming electrodes on said impurity regions, respectively.
Claim 3
Dependent Claim
30 words
A method according to claim 1, wherein said channel layer, said buffer layer, said first control layer, and said second control layer are formed by a molecular beam epitaxy method.
Claim 4
Dependent Claim
32 words
A method according to claim 1, wherein said channel layer, said buffer layer, said first control layer, and said second control layer are formed by a metal organic chemical vapor deposition method.
Claim 5
Dependent Claim
22 words
A method according to claim 1, wherein said channel layer is made of GaAs and said buffer layer is made of AlGaAs.
Claim 6
Dependent Claim
24 words
A method according to claim 1, wherein material of said first control layer is one selected from the group consisting of GaAs and AlGaAs.
Claim 7
Dependent Claim
24 words
A method according to claim 1, wherein material of said second control layer is one selected from the group consisting of GaAs and AlGaAs.
Claim 8
Dependent Claim
39 words
A method according to claim 1, 5 or 6, wherein said forming step of the first control layer and said forming step of the second control layer are carried out simultaneously by using the same doped single crystalline semiconductor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-03-22 | 1991-09-21 | 1992-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-22 | 1995-09-21 | 1996-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-22 | 1999-09-21 | 2000-03-22 | $7700.00 | Window Closed / Lapsed |